Exercise bike



FIG. 1 shows a top front isometric view of an exercise bike in accordance with the present design.

FIG. 2 shows a left side elevation view thereof.

FIG. 3 shows a right side elevation view thereof.

FIG. 4 shows a front elevation view thereof.

FIG. 5 shows a rear elevation view thereof.

FIG. 6 shows a top plan view thereof; and,

FIG. 7 shows a bottom plan view thereof.

The broken lines illustrate portions of the exercise bike that form no part of the claimed design. 

CLAIM I claim the ornamental design for an exercise bike, as shown and described. 